Article ID Journal Published Year Pages File Type
1167898 Analytica Chimica Acta 2009 6 Pages PDF
Abstract

An amperometric sensor based on Ni1−xAlx(OH)2NO3x·nH2O layered double hydroxide (LDH) has been developed for the electrochemical analysis in one step of two herbicides: glyphosate (N-(phosphonomethyl)glycine, Glyp) and glufosinate ((DL-homoalanine-4-yl)-methylphosphinic acid, Gluf). NiAl-LDH was prepared by coprecipitation or by electrodeposition at the Pt electrode surface. Inorganic films were fully characterized by X-ray diffraction, Raman spectroscopy and scanning electron microscopy. Adsorption isotherms of Glyp onto this inorganic lamellar material have been established. Electrocatalytic oxidation of Glyp and Gluf is possible at the Ni3+ centres of the structure. The electrochemical responses of the NiAl-LDH modified electrode were obtained by cyclic voltammetry and chronoamperometry at 0.49 V/SCE as a function of herbicide concentration in 0.1 M NaOH solution. The electrocatalytic response showed a linear dependence on the Glyp concentration ranging between 0.01 and 0.9 mM with a detection limit of 1 μM and sensitivity 287 mA/M cm2. The sensitivity found for Gluf was lower (178 mA/M cm2).

Related Topics
Physical Sciences and Engineering Chemistry Analytical Chemistry
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